Why Ammonium Sulfate?

Ammonium sulfate provides readily available crop nutrients.

On field after field, Sulf-N® ammonium sulfate fertilizers have proven to be an excellent source of the readily-available sulfate sulfur and ammonium nitrogen crops crave. Unlike elemental sulfur, the sulfate sulfur in Sulf-N® is readily available to crop roots, providing them with access to the essential nutrients they need upon application. The ammonium nitrogen in Sulf-N ® is also immediately available for root uptake, and resists nitrogen losses from leaching, volatilization and denitrification.

Sulf-N® ammonium sulfate fertilizer provides two essential nutrients your crops need: ammonium sulfate and sulfate sulfur. It also provides the cost-efficiency you require. As a high-analysis fertilizer offering, it packs 900 pounds of total plant food per ton, making more efficient use of your fertilizer bins. Ammonium sulfate offers many other agronomic advantages over other fertilizer technologies, including:

  • Lower susceptibility to nitrogen loss from leaching, volatilization and denitrification.
  • Higher nutrient efficiency
  • Sulfur that is readily available to plants

Lower susceptibility to nitrogen loss from leaching, volatilization and denitrification.

Higher nutrient efficiency
Sulfur that is readily available to plants

In addition to providing crop nutrition with readily-available sulfate sulfur and ammonium nitrogen, Sulf-N® ammonium sulfate fertilizers assist plants with the uptake of other critical nutrients. In many soils, high soil pH decreases the solubility of phosphorus and critical micronutrients, impeding root uptake. When ammonium is absorbed by the crops, it acidifies their root zones, often unlocking phosphorus and key micronutrients such as zinc, boron, iron, copper and manganese from fertilizers and soil. This benefit, combined with the benefits of sulfate sulfur (24%) and ammonium nitrogen (21%) naturally found in Sulf-N® ammonium sulfate, can help improve overall crop nutrition and yield.

Sulf-N® fertilizers contain sulfate sulfur, which is the only kind of sulfur plant roots can take up. Many sulfur fertilizer products only supply elemental sulfur, or a combination of elemental and sulfate sulfur, with the elemental sulfur not becoming available to crop roots until converted to sulfate. Once in the soil, this conversion can take anywhere from 90 days to several months, which leaves crops hungry for sulfur at critical growth stages. There is no waiting period with Sulf-N® ammonium sulfate, as it contains 100% pure sulfate sulfur nutrition.

Nitrogen enhances crop yield more than any other fertilizer nutrient, and 21% of Sulf-N® ammonium sulfate is nitrogen in the highly-efficient ammonium form. Sulf-N® is immediately available for root uptake. You can even apply it to the soil surface under reduced tillage conditions while resisting the three major causes of nitrogen loss: leaching, volatilization and denitrification.

Less leachable: Positively charged ammonium ions bind to negatively charged soil ions, making Sulf-N® ammonium sulfate less susceptible to leaching.

Resists volatilization: Sulf-N® ammonium sulfate does not need to be incorporated to minimize volatilization loss in most soils types.

Immune to denitrification: The denitrification process that can cause nitrate loss in poorly-drained soils does not affect the availability of the ammonium in Sulf-N®.

Why should you consider Sulf-N® ammonium sulfate your preferred S source?

The sulfate form of sulfur found in Sulf-N® ammonium sulfate is immediately available for plant uptake. The elemental form of sulfur can take months before it becomes available for use by plants.


Because it provides nutrients that are immediately available for uptake by the plant, Sulf-N® ammonium sulfate can work in early or mid-season fertilizer blends for crops such as corn and cotton. Research has also shown a benefit of a fall Sulf-N® ammonium sulfate application for winter wheat and continuous corn fields.  Sulf-N® ammonium sulfate can be applied on soybeans any time between pre-plant and V4/V5 stages at rates between 75-120 pounds per acre to boost early growth and nodulation.  Across crops, Sulf-N® ammonium sulfate can provide the nitrogen and sulfur that crops need when they need it.


Sulf-N® ammonium sulfate has worked consistently for farmers and agronomists, season after season. It’s proven and reliable crop nutrition in a safe, easy to apply form.  For decades, AdvanSix has sponsored university research to learn more about the benefits of Sulf-N® ammonium sulfate across a wide variety of crops and growing conditions.  There’s a reason why almost every retailer carries Sulf-N® ammonium sulfate: it routinely delivers a return on your investment.


By offering both ammonium nitrogen and sulfate sulfur in one granule, Sulf-N® ammonium sulfate promptly delivers a key nutritional pair essential for plant development. And because Sulf-N® ammonium sulfate granules may be applied on the surface without incorporation, farmers can time applications around weather events, giving them flexibility to ensure these nutrients are sufficient when the plant needs them.


Sulf-N® ammonium sulfate is widely stocked by retailers because it is a proven, versatile fertilizer for high yielding crop systems. Whether it is used for fall, spring, or mid-season application, Sulf-N® ammonium sulfate is available for farmers to help ensure their crops have the nutrition they need to maximize their yield potential.

Granular Ammonium Sulfate vs. Granular Elemental Sulfur

What is Ammonium Sulfate? (AMS)

A fertilizer containing 21% ammonium-N and 24% sulfate-S

  • Water-soluble
  • Readily plant-available S
  • May be used to correct in-season S deficiencies

What is Elemental Sulfur? (S)

Sulfur bentonite or co-granulated sulfur product
  • Water-insoluble
  • Not available unless ES is oxidized to SO4-S, disintegrated ES particles are clustered without dispersion, impeding initial ES oxidation
  • Once the particles get to oxidize they become available

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